import java.util.Arrays;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * User: 12629
 * Date: 2021/11/4
 * Time: 9:14
 * Description:
 */
class A {
    private int a;
    public int b;

    private void func() {

    }
    public void func2() {
        func();
    }
}
class B extends A {
    public void test() {
        System.out.println(super.b);
        super.func2();
    }
}
public class TestDemo {


    public static void func(String str1) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < str1.length(); i++) {
            char ch = str1.charAt(i);
            //sb.toString()   contains
            if(!sb.toString().contains(ch+"")) {
                sb.append(ch);
            }
        }
        System.out.println(sb);
    }

    public static String func2(String str) {
        int[] array = new int[127];
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            //说明当前字符没有出现过
            if(array[ch] == 0) {
                sb.append(ch);
                array[ch] = 1;
            }
        }
        return sb.toString();
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextLine()) {
            String str = scan.nextLine();
            func(str);
        }
    }




    public static boolean isAdmin(String userId){
        return userId.toLowerCase()=="admin";
    }

    public static void func1(int[] array) {
        array = new int[10];
    }

    public static void func2(int[] array) {
        array[0] = 9;
    }

    public static void main2(String[] args) {
        boolean b=false?false:true==true?true:true;
        System.out.println(b);

    }
    public static void main1(String[] args){
        int[] array = {1,2,3,4,5,6,7};
        System.out.println(Arrays.toString(array));
        func2(array);
        System.out.println(Arrays.toString(array));

        ///System.out.println(isAdmin("Admin"));
    }
}
